1. Field of the Invention
The present invention relates to a soil release agent for dry cleaning.
2. Related Art
When a material having a fluoroalkyl group is coated on a solid substance surface, the substance exhibits high water- and oil-repellency due to a remarkably lowered surface energy. In view of this property, a polymer comprising a fluorine-containing polymerizable monomer such as a (meth)acrylate having a fluoroalkyl group is commercially available as a water- and oil-repellent for treating a textile such as clothes in the form of an aqueous dispersion or a solution in an organic solvent. The water- and oil-repellent is used, for example, for clothes such as a raincoat.
However, soil is always adhered to the clothes treated with the water- and oil-repellent, when the clothes are worn. The soil adhered to the clothes cannot be easily removed even if the clothes are washed, since a detergent is repelled at surfaces of the clothes.
When the clothes having the soil are washed in a water at home, the aqueous soil can be easily removed. But, it is known that the oily soil can be removed with difficulty higher than in the case of the clothes which is not treated with the water- and oil-repellent. Accordingly, the water- and oil repellent is not suitable for the clothes to which the soil easily adheres, such as work clothes.
In order to solve the above problem, a soil release agent (also referred to as "SR agent") has been developed and already practically used. In order to remove the oily soil described above, the surfaces of the clothes are treated so that they exhibit a hydrophilic nature together with oil repellency. Accordingly, the soil release agent is prepared by copolymerizing an oil-repellent polymerizable monomer having A fluoroalkyl group with a hydrophilic polymerizable monomer. In the clothes treated with this soil release agent, the oily soil can be easily removed from the clothes in water by household laundering.
The improvement of the soil release agent is being continued so as to enhance an initial soil release property and durability.
In the continuation of the improvement, the soil release treatment for the clothes which are subjected to the dry cleaning is hardly thought and almost no documents describing this are present. The soil release agent having excellent properties and suitable for the dry cleaning is not practically used.